Here comes a catastrophe, ready or not

12/08/1998

CORVALLIS, Ore. - The Pacific Northwest is facing a catastrophe that could cause thousands of fatalities and tens of billions of dollars of damage, an Oregon State University expert says - and despite some progress made in the last few years to prepare for this, a majority of people still don't seem to care.

Robert Yeats, a professor emeritus of geology at OSU and author of a new book titled "Living With Earthquakes in the Pacific Northwest," says the argument is settled about whether or not this region is facing disastrous earthquakes.

The real issue now is whether enough is being done at every level - government, building codes, disaster planning and individual preparation - to prevent the massive loss of life and economic devastation from the huge earthquake that, scientifically, is a near certainty.

"The sheer size of the earthquake problem dwarfs other concerns we face," Yeats says in the preface of his book, which he said was written for the general public as "part handbook, part scientific explanation, part call-to-action."

"In some respects, telling my Northwest neighbors that we have an earthquake problem has been like telling them about carpenter ants in the basement," Yeats wrote. "I began to feel like the watchman on the castle walls, warning about the barbarians at the gate, begging people to take me seriously."

For Yeats, his role as watchman and town crier is the culmination of a distinguished scientific career in which he was one of the very first experts to warn almost 15 years ago that major earthquakes were a real concern for the Pacific Northwest and not just something that happened in California.

Since that time, as study after study is done and the evidence begins to mount in everything from buried salt marshes to Japanese tsunami records, a surprisingly precise picture is beginning to emerge about the risks faced from earthquakes in the Pacific Northwest.

It is not pretty, Yeats says.

A major crustal fault runs at shallow depths right under downtown Seattle that about 1,000 years ago apparently caused a magnitude 7 earthquake, big enough if it were to recur today to cause catastrophic destruction. Other significant faults, about which the activity level is less clear, run next to downtown Portland and directly underneath Crescent Valley High School outside Corvallis. There are literally hundreds of mapped faults all over Oregon, Washington and southwestern British Columbia, and probably many more that scientists don't even know.

And then, of course, there's the Big One - the subduction zone earthquakes which lurk off the shore of the Pacific Northwest, which apparently last struck on a wintry January night in the year 1700, which have an apparent recurrence interval of 200 to 1,000 years, and which average about every 500 years.

"There is a scientific consensus on the risk we face from a subduction zone earthquake and there is now no serious doubt that we are vulnerable," Yeats said. "Right now, the debate is primarily whether a long section of the subduction zone fault will release all at once, generating about a magnitude 9 earthquake, or in separate segments that would yield magnitude 8 earthquakes."

That's an important debate, Yeats said, and one that researchers may have an answer to within a few years. In his book the question of a single magnitude 9 versus several magnitude 8 earthquakes is referred to as an "instant of catastrophe or decade of terror."

"A magnitude 9 subduction zone earthquake could trash the whole Pacific Coast from Canada to California and possibly wipe out the region's insurance industry," Yeats said. "In my own analysis I'm still a little bit on the fence, but I lean towards the evidence that a magnitude 9 is most likely."

Yeats' 310-page book outlines all of these issues and more - the basics of plate tectonics, the origin of earthquakes, the difference between crustal and subduction zone earthquakes, the special risks of tsunamis and soil liquefaction, earthquake insurance, government planning, earthquake forecasting and prediction, building code issues, and, of course, what average homeowners can do to help prepare their dwelling and family for an earthquake.

"This book was written for the general public, and I'm really hoping to raise public awareness about these issues and get people to take them more seriously," he said. "The book actually evolved from a course I taught at OSU in the university's program to educate people on the impact of science and technology on society. An informed citizenry is the real key to this issue and many other problems."

Yeats is recognized as one of the world's premier experts on earthquakes, especially those of the Pacific Northwest, California and the Pacific Rim, and has traveled from the United States to Japan, New Zealand, India and many other nations and continents to study this geologic phenomenon. In 1984 he was among the first scientists to begin warning of the potential for great earthquakes in the Pacific Northwest.

As a result of those efforts and similar work by many other scientists, Oregon now actually has made considerable progress in preparing for this problem. The coast of the Oregon, for instance, now has the highest "seismic activity" ratings for purposes of building codes and other issues, the same as those of southern California.

Yeats' book, which costs $21.95 plus shipping and handling, was published by the OSU Press. It can be ordered by calling (800) 426-3797. In Canada, contact the University of British Columbia Press, (604) 822-5959.

"The success of this book will depend on how successful I am in convincing individuals and communities to fortify themselves against a catastrophe that may not strike in our lifetimes," Yeats said in his book. "The book will be measured after the next large earthquake, when we ask ourselves afterwards, were we ready?"